Populus spp. (Pappel, poplar)
Nomenclature etc. SALICACEAE. Populus alba L., P. canescens Sm., P. deltoides Marsh., P. grandidentata Michx., P. heterophylla L., P. nigra L., P. tremula L., P. tremuloides Michx. Trade and local names: Zitterpappel, Aspe, Espe, Silberpappel, Euphrat-Pappel, Schwarzpappel (B), Aspen, Popular, Black popular (GB), Abeel espen, Populieren (NL), Peuplier tremble (F), Titreh kavak (TR), Pioppo tremolo (I), Alamo temblon (E), Topol cerny (CS), Topola crna (YU), Plop negru (RO), Fekete ny r (H) Cottonwood (USA).
Tree. Geographic distribution: Europe, excl. Mediterranean, Mediterranean incl. N. Africa and Middle East, temperate Asia, India, Pakistan, Sri Lanka, and North America.
General. Growth ring boundaries distinct. Heartwood basically yellow to white or grey. Sapwood colour similar to heartwood colour, or distinct from heartwood colour. Basic specific gravity 0.36–0.45–0.56 g/cm³.
Vessels. Wood diffuse-porous. Vessels in multiples, commonly short (2–3 vessels) radial rows. Average tangential vessel diameter 40–65–95 µm. Average number of vessels/mm² 25–45–70. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 10–11 µm. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, restricted to marginal rows. Helical thickenings absent. Tyloses in vessels present (few), thinwalled.
Tracheids and fibres. Fibres very thin-walled. Average fibre length 220–1100–2100 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered.
Axial parenchyma. Axial parenchyma banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide.
Rays. Rays 8–13 per tangential mm, exclusively uniseriate. Aggregate rays absent. Rays composed of a single cell type. Homocellular ray cells procumbent.
Storied structures. Storied structure absent.
Secretory structures. Intercellular canals absent.
Mineral inclusions. Crystals not observed. Silica not observed.
Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).